The preparation of optically active alpha-aminonitriles is the key step in the preparation of many aminoacids. See for example the publications by K. Harada or Harada et al in J. ORG. CHEM. 31, 1956 (1966); 32, 1790 (1967); 32, 1794 (1967; 33, 4526 (1968); NATURE 200, 1201 (1963); or NATURWISS 51, 106 (1964). In general, most of the reported methods disclose either the reaction of optically active alpha-methylbenzylamine with a racemic cyanohydrin (NATURE 200, 1201 or NATURWISS 51, 106) or the addition of hydrogen cyanide gas to an optically active Schiff base (M. Patel et al CAN. J. CHEM. 48, 1881, 1970). Ojima et al, CHEM. LETT. 331, 737 (1975), have shown that trimethylsilyl cyanide (TMSCN) reacts with aldimines in the presence of a catalytic amount of AlCl.sub.3 to give N-TMS-alpha-aminonitriles. Stout et al have recently reported the direct preparation of optically active aminonitriles from aldehydes (J. ORG. CHEM. 48, 5369, 1983).